Additive manufacturing method for building three-dimensional objects with core-shell arrangements, and three-dimensional objects thereof

Abstract

A consumable filament for use in an extrusion-based additive manufacturing system, where the consumable filament comprises a core portion of a first thermoplastic material, and a shell portion of a second thermoplastic material that is compositionally different from the first thermoplastic material, where the consumable filament is configured to be melted and extruded to form roads of a plurality of solidified layers of a three-dimensional object, and where the roads at least partially retain cross-sectional profiles corresponding to the core portion and the shell portion of the consumable filament.

The invention claimed is: 
     
       1. A three-dimensional object built with an extrusion-based additive manufacturing system, the three-dimensional object comprising:
 a plurality of solidified layers each comprising roads formed from a flowable consumable material that exits an extrusion tip of the extrusion-based additive manufacturing system, wherein the flowable consumable material exiting the extrusion tip comprises a core material and a shell material that is compositionally different from the core material, and wherein the shell material encases the core material to provide an interface between the core material and the shell material; and 
 wherein at least a portion of the roads of the plurality of solidified layers comprise core regions of the core material and shell regions of the shell material, and wherein the core regions and the shell regions substantially retain cross-sectional profiles corresponding to the interface between the core material and the shell material of the flowable consumable material. 
 
     
     
       2. The three-dimensional object of  claim 1 , wherein the core material and the shell material at least partially interdiffuse at the interface between the core material and the shell material. 
     
     
       3. The three-dimensional object of  claim 1 , wherein the core material comprises a first thermoplastic polymer. 
     
     
       4. The three-dimensional object of  claim 3 , wherein the shell material comprises a colorant. 
     
     
       5. The three-dimensional object of  claim 4 , wherein the shell material further comprises a second thermoplastic polymer. 
     
     
       6. The three-dimensional object of  claim 5 , wherein the first thermoplastic polymer of the core material comprises a first semi-crystalline polymeric material having a first peak crystallization temperature, and wherein the second thermoplastic polymer of the shell material comprises a second semi-crystalline polymeric material having a second peak crystallization temperature that is different than the first peak crystallization temperature. 
     
     
       7. The three-dimensional object of  claim 1 , wherein substantially all of the roads of the plurality of solidified layers comprise the core regions and the shell regions that retain cross-sectional profiles corresponding to the interface between the core material and the shell material of the flowable consumable material. 
     
     
       8. A three-dimensional object built with an extrusion-based additive manufacturing system, the three-dimensional object comprising:
 a plurality of solidified layers each comprising roads formed from a flowable consumable material that exits an extrusion tip of the extrusion-based additive manufacturing system, wherein the flowable consumable material exiting the extrusion tip comprises a core material and a shell material that is compositionally different from the core material, and wherein the shell material encases the core material to provide an interface between the core material and the shell material; and 
 wherein at least a portion of the roads of the plurality of solidified layers comprise core regions of the core material and shell regions of the shell material, and wherein the core regions and the shell regions are substantially maintained after extrusion into the plurality of solidified layers. 
 
     
     
       9. The object of  claim 8 , wherein the shell comprises a first semi-crystalline polymer and the core comprises the first semi-crystalline polymer and a crystallization inhibitor. 
     
     
       10. The object of  claim 8 , wherein the shell comprises a first semi-crystalline polymer and one or more nucleating agents and the core comprises the first semi-crystalline polymer. 
     
     
       11. The object of  claim 8 , wherein the core comprises a majority of a first semi-crystalline polymer and the shell comprises a majority of a second semi-crystalline polymer. 
     
     
       12. The object of  claim 11 , wherein a difference in melting points of the first semi-crystalline polymer and the second semi-crystalline polymer is about 8° C. or less. 
     
     
       13. The object of  claim 11 , wherein a difference in melting points of the first semi-crystalline polymer and the second semi-crystalline polymer is about 3° C. or less. 
     
     
       14. The object of  claim 8 , wherein the core and the shell each comprise polyamides, polyethylenes, polypropylenes, polyetheretherketones, polyetherarylketones, perfluoroalkoxys, polychlorotrifluoroethylenes, polyphenylene sulfides, fluorinated ethylene propylenes, polytetrafluoroethylenes, ethylene-tetrafluoroethylenes, polyvinylidene fluorides, and ethylene-chlorortifluoroethylenes, copolymers thereof, and combinations thereof. 
     
     
       15. The object of  claim 14 , wherein the polyamides comprise aliphatic nylon polyamides, such as nylon 6, nylon 6-6, nylon 6-10, nylon 6-12, nylon 10, nylon 10-10, nylon 11, nylon 12, and combinations thereof, wherein the polyethylenes include low-density polyethylene, medium-density polyethylene, high-density polyethylene, and combinations thereof, and wherein the polypropylenes include isotactic polypropylenes, syndiotactic polypropylenes, branched and linear variations thereof, and combinations thereof. 
     
     
       16. A three-dimensional object built with an extrusion-based additive manufacturing system, the three-dimensional object comprising:
 a plurality of solidified layers each comprising roads formed from a flowable consumable material that exits an extrusion tip of the extrusion-based additive manufacturing system, wherein the flowable consumable material exiting the extrusion tip comprises a core material and a shell material that is different from the core material, and wherein the shell material encases the core material to provide an interface between the core material and the shell material wherein the core material and the shell material are semi-crystalline materials having peak crystallization temperatures that have at least a 2° C. or greater difference; and 
 wherein at least a portion of the roads of the plurality of solidified layers comprise core regions of the core material and shell regions of the shell material, and wherein the core regions and the shell regions are substantially maintained after extrusion into the plurality of solidified layers. 
 
     
     
       17. The three-dimensional object of  claim 16 , wherein the peak crystallization temperatures of the semi-crystalline core material and the semi-crystalline shell material are at least a 10° C. or greater in difference. 
     
     
       18. The three-dimensional object of  claim 16 , wherein the peak crystallization temperatures of the semi-crystalline core material and the semi-crystalline shell material are less than 25° C. or less in difference.